In the past, hay was cut in the field and left to dry. When dried sufficiently it can then be baled. The timing can be critical in that the hay must be cut at a certain time when it has reached a certain stage of development, and then it must be dried in the field sufficiently and thoroughly enough for it to be ready for baling. The farmer does not want the cut hay left too long in the field as it dries because this can occupy valuable field time and possibly result in fewer crops being harvested in one season. It is also important that the hay once cut be baled before the next rain. Otherwise, the hay can be ruined or at least an even longer drying time is required.
Various farm implements have been used to shorten the field drying time. For example, hay tedders have been used which essentially stir or mix the hay up as it lies on the ground. They do not turn the hay over completely for maximum drying. Hay rakes also have been used to turn the hay over, but then only partially over. These rakes or similar rakes also are used to gather the cut hay into windrows. These raked windrows or swaths should be of a convenient width for ease in baling. Neither the rakes nor the tedders have proven to be satisfactory though for a number of reasons. First, they do not completely turn the hay over so that it can dry in the shortest time period. Second, they do not work as cleanly as desired, in other words, they roll up more trash, rocks, and other debris and mix it in with the hay, especially if forage is cut with a forage harvester for filling a silo. Third, these prior devices usually are designed so that the pulling implement, typically a tractor, runs over the hay thereby crushing it and knocking off the protein-laden leaves, which is undesirable. Fourth, these devices typically do not place the hay in swaths of predetermined desired widths to maximize the efficiency of the baling machines, especially for the four and five foot round hay balers.